In an effort to improve the cooling scheme of a stage 1 gas turbine bucket, a “pants-leg” shaped core has been used in the bucket shank portion of the shell die to form a pair of cooling passages in place of a previous design utilized to form a plurality of radial cooling holes. In the casting process, wax inserts (cores) are covered in plaster and then the wax is melted away. When the thin legs of the wax core were covered with plastic, however, the core tended to drift significantly, resulting in wall thicknesses in the shank portion of the bucket being out of tolerance.
Core stabilizing devices or “printouts” for improving the yield of a bucket casting process have been previously used in stage 2 buckets, but with a different core design and in a different location relative to the so-called angel wings on the exterior of the shank portion of the bucket. Because of the different design of the stage 1 and stage 2 buckets, it was not possible to simply scale up the stage 2 bucket core for use in the stage 1 bucket casting process.
Accordingly, there is a need for a core constructed to better secure the core in the place, especially during the plastic stage of the casting process.